1. Field of the Invention
The present invention relates generally to a cooling device for cooling a semiconductor element which generates a substantial quantity of heat and, in particular but not exclusively, to a compact, easy-to-handle and efficient cooling device for cooling such a semiconductor element by utilization of a change in phase between a liquid phase and a vapor phase of a refrigerant.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 2000-208683 discloses a natural circulation type cooling device for cooling a heating element by utilization of a change in phase between a liquid phase and a vapor phase of a refrigerant, as shown in FIG. 1. The cooling device shown therein is provided with a refrigerant tank 20 for storing a liquid refrigerant, a radiator 22 for radiating heat from a vapor refrigerant, and a fan (not shown) for cooling the radiator 22.
Because this cooling device is not provided with an inverter-controlled refrigerant pump, it controls the required cooling power merely by changing the number of revolutions of the fan depending on the amount of heat generated by the semiconductor element.
Furthermore, Japanese Laid-Open Patent Publication No. 2000-208683 lacks any disclosure of an avoidance system in an abnormal situation.